In 1939, Adolf Hitler commissioned the Friedrich Krupp A.G. company of Essen, Germany to build a gun that would breach the French Maginot line. They responded with the "Gustav Gun," the largest gun ever built.

Named after the head of the Krupp family, Gustav Krupp von Bohlen und Halbach, the Gustav Gun weighed in at a massive 1344 tons, so heavy that even though it was attached to a rail car, it still had to be disassembled before moving so as to not destroy the twin set of tracks as it passed over. This 4-story behemoth stood 20 feet wide and 140 feet long. Its 500 man crew, commanded by a Major-General (that's two stars), needed nearly three full days (54 hours, to be exact) to set it up and prep for firing. But when it did fire, whoowhee, hold on to your hat.